net/sctp/endpointola.c

   1 /* SCTP kernel reference Implementation
   2  * Copyright (c) 1999-2000 Cisco, Inc.
   3  * Copyright (c) 1999-2001 Motorola, Inc.
   4  * Copyright (c) 2001-2002 International Business Machines, Corp.
   5  * Copyright (c) 2001 Intel Corp.
   6  * Copyright (c) 2001 Nokia, Inc.
   7  * Copyright (c) 2001 La Monte H.P. Yarroll
   8  *
   9  * This file is part of the SCTP kernel reference Implementation
  10  *
  11  * This abstraction represents an SCTP endpoint.
  12  *
  13  * This file is part of the implementation of the add-IP extension,
  14  * based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
  15  * for the SCTP kernel reference Implementation.
  16  *
  17  * The SCTP reference implementation is free software;
  18  * you can redistribute it and/or modify it under the terms of
  19  * the GNU General Public License as published by
  20  * the Free Software Foundation; either version 2, or (at your option)
  21  * any later version.
  22  *
  23  * The SCTP reference implementation is distributed in the hope that it
  24  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  25  *                 ************************
  26  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  27  * See the GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with GNU CC; see the file COPYING.  If not, write to
  31  * the Free Software Foundation, 59 Temple Place - Suite 330,
  32  * Boston, MA 02111-1307, USA.
  33  *
  34  * Please send any bug reports or fixes you make to the
  35  * email address(es):
  36  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  37  *
  38  * Or submit a bug report through the following website:
  39  *    http://www.sf.net/projects/lksctp
  40  *
  41  * Written or modified by:
  42  *    La Monte H.P. Yarroll <piggy@acm.org>
  43  *    Karl Knutson <karl@athena.chicago.il.us>
  44  *    Jon Grimm <jgrimm@austin.ibm.com>
  45  *    Daisy Chang <daisyc@us.ibm.com>
  46  *    Dajiang Zhang <dajiang.zhang@nokia.com>
  47  *
  48  * Any bugs reported given to us we will try to fix... any fixes shared will
  49  * be incorporated into the next SCTP release.
  50  */
  51
  52 #include <linux/types.h>
  53 #include <linux/sched.h>
  54 #include <linux/slab.h>
  55 #include <linux/in.h>
  56 #include <linux/random.h>       /* get_random_bytes() */
  57 #include <linux/crypto.h>
  58 #include <net/sock.h>
  59 #include <net/ipv6.h>
  60 #include <net/sctp/sctp.h>
  61 #include <net/sctp/sm.h>
  62
  63 /* Forward declarations for internal helpers. */
  64 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep);
  65
  66 /*
  67  * Initialize the base fields of the endpoint structure.
  68  */
  69 static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
  70                                                 struct sock *sk, int gfp)
  71 {
  72         struct sctp_sock *sp = sctp_sk(sk);
  73         memset(ep, 0, sizeof(struct sctp_endpoint));
  74
  75         /* Initialize the base structure. */
  76         /* What type of endpoint are we?  */
  77         ep->base.type = SCTP_EP_TYPE_SOCKET;
  78
  79         /* Initialize the basic object fields. */
  80         atomic_set(&ep->base.refcnt, 1);
  81         ep->base.dead = 0;
  82         ep->base.malloced = 1;
  83
  84         /* Create an input queue.  */
  85         sctp_inq_init(&ep->base.inqueue);
  86
  87         /* Set its top-half handler */
  88         sctp_inq_set_th_handler(&ep->base.inqueue,
  89                                 (void (*)(void *))sctp_endpoint_bh_rcv, ep);
  90
  91         /* Initialize the bind addr area */
  92         sctp_bind_addr_init(&ep->base.bind_addr, 0);
  93         rwlock_init(&ep->base.addr_lock);
  94
  95         /* Remember who we are attached to.  */
  96         ep->base.sk = sk;
  97         sock_hold(ep->base.sk);
  98
  99         /* Create the lists of associations.  */
 100         INIT_LIST_HEAD(&ep->asocs);
 101
 102         /* Set up the base timeout information.  */
 103         ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
 104         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 105                 SCTP_DEFAULT_TIMEOUT_T1_COOKIE;
 106         ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 107                 SCTP_DEFAULT_TIMEOUT_T1_INIT;
 108         ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =
 109                 msecs_to_jiffies(sp->rtoinfo.srto_initial);
 110         ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
 111         ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
 112
 113         /* sctpimpguide-05 Section 2.12.2
 114          * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
 115          * recommended value of 5 times 'RTO.Max'.
 116          */
 117         ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
 118                 = 5 * msecs_to_jiffies(sp->rtoinfo.srto_max);
 119
 120         ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] =
 121                 SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
 122         ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 123                 SCTP_DEFAULT_TIMEOUT_SACK;
 124         ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
 125                 sp->autoclose * HZ;
 126
 127         /* Use SCTP specific send buffer space queues.  */
 128         ep->sndbuf_policy = sctp_sndbuf_policy;
 129         sk->sk_write_space = sctp_write_space;
 130         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 131
 132         /* Initialize the secret key used with cookie. */
 133         get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
 134         ep->last_key = ep->current_key = 0;
 135         ep->key_changed_at = jiffies;
 136
 137         return ep;
 138 }
 139
 140 /* Create a sctp_endpoint with all that boring stuff initialized.
 141  * Returns NULL if there isn't enough memory.
 142  */
 143 struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, int gfp)
 144 {
 145         struct sctp_endpoint *ep;
 146
 147         /* Build a local endpoint. */
 148         ep = t_new(struct sctp_endpoint, gfp);
 149         if (!ep)
 150                 goto fail;
 151         if (!sctp_endpoint_init(ep, sk, gfp))
 152                 goto fail_init;
 153         ep->base.malloced = 1;
 154         SCTP_DBG_OBJCNT_INC(ep);
 155         return ep;
 156
 157 fail_init:
 158         kfree(ep);
 159 fail:
 160         return NULL;
 161 }
 162
 163 /* Add an association to an endpoint.  */
 164 void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 165                             struct sctp_association *asoc)
 166 {
 167         struct sock *sk = ep->base.sk;
 168
 169         /* Now just add it to our list of asocs */
 170         list_add_tail(&asoc->asocs, &ep->asocs);
 171
 172         /* Increment the backlog value for a TCP-style listening socket. */
 173         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
 174                 sk->sk_ack_backlog++;
 175 }
 176
 177 /* Free the endpoint structure.  Delay cleanup until
 178  * all users have released their reference count on this structure.
 179  */
 180 void sctp_endpoint_free(struct sctp_endpoint *ep)
 181 {
 182         ep->base.dead = 1;
 183         sctp_endpoint_put(ep);
 184 }
 185
 186 /* Final destructor for endpoint.  */
 187 static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 188 {
 189         SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
 190
 191         ep->base.sk->sk_state = SCTP_SS_CLOSED;
 192
 193         /* Unlink this endpoint, so we can't find it again! */
 194         sctp_unhash_endpoint(ep);
 195
 196         /* Free up the HMAC transform. */
 197         if (sctp_sk(ep->base.sk)->hmac)
 198                 sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
 199
 200         /* Cleanup. */
 201         sctp_inq_free(&ep->base.inqueue);
 202         sctp_bind_addr_free(&ep->base.bind_addr);
 203
 204         /* Remove and free the port */
 205         if (sctp_sk(ep->base.sk)->bind_hash)
 206                 sctp_put_port(ep->base.sk);
 207
 208         /* Give up our hold on the sock. */
 209         if (ep->base.sk)
 210                 sock_put(ep->base.sk);
 211
 212         /* Finally, free up our memory. */
 213         if (ep->base.malloced) {
 214                 kfree(ep);
 215                 SCTP_DBG_OBJCNT_DEC(ep);
 216         }
 217 }
 218
 219 /* Hold a reference to an endpoint. */
 220 void sctp_endpoint_hold(struct sctp_endpoint *ep)
 221 {
 222         atomic_inc(&ep->base.refcnt);
 223 }
 224
 225 /* Release a reference to an endpoint and clean up if there are
 226  * no more references.
 227  */
 228 void sctp_endpoint_put(struct sctp_endpoint *ep)
 229 {
 230         if (atomic_dec_and_test(&ep->base.refcnt))
 231                 sctp_endpoint_destroy(ep);
 232 }
 233
 234 /* Is this the endpoint we are looking for?  */
 235 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
 236                                                const union sctp_addr *laddr)
 237 {
 238         struct sctp_endpoint *retval;
 239
 240         sctp_read_lock(&ep->base.addr_lock);
 241         if (ep->base.bind_addr.port == laddr->v4.sin_port) {
 242                 if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
 243                                          sctp_sk(ep->base.sk))) {
 244                         retval = ep;
 245                         goto out;
 246                 }
 247         }
 248
 249         retval = NULL;
 250
 251 out:
 252         sctp_read_unlock(&ep->base.addr_lock);
 253         return retval;
 254 }
 255
 256 /* Find the association that goes with this chunk.
 257  * We do a linear search of the associations for this endpoint.
 258  * We return the matching transport address too.
 259  */
 260 static struct sctp_association *__sctp_endpoint_lookup_assoc(
 261         const struct sctp_endpoint *ep,
 262         const union sctp_addr *paddr,
 263         struct sctp_transport **transport)
 264 {
 265         int rport;
 266         struct sctp_association *asoc;
 267         struct list_head *pos;
 268
 269         rport = paddr->v4.sin_port;
 270
 271         list_for_each(pos, &ep->asocs) {
 272                 asoc = list_entry(pos, struct sctp_association, asocs);
 273                 if (rport == asoc->peer.port) {
 274                         sctp_read_lock(&asoc->base.addr_lock);
 275                         *transport = sctp_assoc_lookup_paddr(asoc, paddr);
 276                         sctp_read_unlock(&asoc->base.addr_lock);
 277
 278                         if (*transport)
 279                                 return asoc;
 280                 }
 281         }
 282
 283         *transport = NULL;
 284         return NULL;
 285 }
 286
 287 /* Lookup association on an endpoint based on a peer address.  BH-safe.  */
 288 struct sctp_association *sctp_endpoint_lookup_assoc(
 289         const struct sctp_endpoint *ep,
 290         const union sctp_addr *paddr,
 291         struct sctp_transport **transport)
 292 {
 293         struct sctp_association *asoc;
 294
 295         sctp_local_bh_disable();
 296         asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
 297         sctp_local_bh_enable();
 298
 299         return asoc;
 300 }
 301
 302 /* Look for any peeled off association from the endpoint that matches the
 303  * given peer address.
 304  */
 305 int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
 306                                 const union sctp_addr *paddr)
 307 {
 308         struct list_head *pos;
 309         struct sctp_sockaddr_entry *addr;
 310         struct sctp_bind_addr *bp;
 311
 312         sctp_read_lock(&ep->base.addr_lock);
 313         bp = &ep->base.bind_addr;
 314         list_for_each(pos, &bp->address_list) {
 315                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
 316                 if (sctp_has_association(&addr->a, paddr)) {
 317                         sctp_read_unlock(&ep->base.addr_lock);
 318                         return 1;
 319                 }
 320         }
 321         sctp_read_unlock(&ep->base.addr_lock);
 322
 323         return 0;
 324 }
 325
 326 /* Do delayed input processing.  This is scheduled by sctp_rcv().
 327  * This may be called on BH or task time.
 328  */
 329 static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
 330 {
 331         struct sctp_association *asoc;
 332         struct sock *sk;
 333         struct sctp_transport *transport;
 334         struct sctp_chunk *chunk;
 335         struct sctp_inq *inqueue;
 336         sctp_subtype_t subtype;
 337         sctp_state_t state;
 338         int error = 0;
 339
 340         if (ep->base.dead)
 341                 return;
 342
 343         asoc = NULL;
 344         inqueue = &ep->base.inqueue;
 345         sk = ep->base.sk;
 346
 347         while (NULL != (chunk = sctp_inq_pop(inqueue))) {
 348                 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
 349
 350                 /* We might have grown an association since last we
 351                  * looked, so try again.
 352                  *
 353                  * This happens when we've just processed our
 354                  * COOKIE-ECHO chunk.
 355                  */
 356                 if (NULL == chunk->asoc) {
 357                         asoc = sctp_endpoint_lookup_assoc(ep,
 358                                                           sctp_source(chunk),
 359                                                           &transport);
 360                         chunk->asoc = asoc;
 361                         chunk->transport = transport;
 362                 }
 363
 364                 state = asoc ? asoc->state : SCTP_STATE_CLOSED;
 365
 366                 /* Remember where the last DATA chunk came from so we
 367                  * know where to send the SACK.
 368                  */
 369                 if (asoc && sctp_chunk_is_data(chunk))
 370                         asoc->peer.last_data_from = chunk->transport;
 371                 else
 372                         SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
 373
 374                 if (chunk->transport)
 375                         chunk->transport->last_time_heard = jiffies;
 376
 377                 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
 378                                    ep, asoc, chunk, GFP_ATOMIC);
 379
 380                 if (error && chunk)
 381                         chunk->pdiscard = 1;
 382
 383                 /* Check to see if the endpoint is freed in response to
 384                  * the incoming chunk. If so, get out of the while loop.
 385                  */
 386                 if (!sctp_sk(sk)->ep)
 387                         break;
 388         }
 389 }